This grant application responds to PAR-12-252: NIOSH Exploratory and/or Developmental Grant Program (R21). Exposure to airborne biological agents is known to cause a wide range of respiratory and other health disorders in occupational and general populations. The main goal of this research is to improve our ability to assess exposures to biological agents by designing and developing an advanced personal electrostatic bioaerosol sampler (PEBS). This new personal sampler will be lightweight, self-contained (without a cumbersome external vacuum pump), and capable of measuring exposures for up to several hours at high sampling flow rates. We hypothesize that a combination of electrostatic collection method, superhydrophobic collection surface and specific sampler design will enable efficient microorganism collection at h high flow rates and extended periods of time thus allowing a more accurate assessment of personal exposures to even to low microorganism concentrations - a feature currently lacking in personal bioaerosol samplers. This will substantially improve our ability to identify exposure risks and protect affected populations. The sampler will be designed and developed using computational fluid dynamics and then manufactured using 3D printing. The prototype sampler will first be tested in a laboratory with non-biological and biological particles; then its performance will be compared with that of other samplers in a laboratory and indoor occupational environment. This proposal responds to several NORA's Priority Research Agendas: National Agriculture, Forestry, and Fishing; National Services; National Transportation, Warehousing, and Utilities by answering their call to improve exposure assessment to occupational agents (e.g., biological agents) and to prevent and reduce work-related respiratory infectious diseases. The proposal also responds to several cross-sector programs, e.g., E exposure assessment and Respiratory diseases. This proposal responds to NIOSH r2P initiative by developing an innovative tool that will enable improved assessment of personal exposures to biological air contaminants. The new exposure assessment technology will eventually lead to better worker health protection. Upon further development, the technology will be transferred for implementation in the workplace. In future studies we will work collaboratively with various stakeholders to verify and improve effectiveness of this technology for field applications. The output of the study will be an advanced tool for occupational environments: a prototype of a new personal bioaerosol sampler, and publications and presentations describing the technology and its performance. We expect that intermediate outcomes will include a patent on this technology, citations of the literature describing the sampler and finally adoption of the technology in practice. Since the sampler will enable a more accurate exposure assessment, the end outcome of this research is expected to be a better understanding of exposures to hazardous biological particles eventually leading to better health protection.